30 Questions
What is the primary factor that determines the resistance to airflow in the lungs?
The diameter of the bronchiole
How does the relationship between flow, pressure, and resistance in pulmonary ventilation typically occur?
F = ΔP ÷ R
What happens to the resistance in the airways when the bronchiole constricts?
It increases
In healthy lungs, what is typically true about airway resistance?
It offers little resistance to airflow
What is the relationship between gas flow and resistance in pulmonary ventilation?
Gas flow is inversely proportional to resistance
Why is resistance usually insignificant in the first part of the conducting zone?
Due to the large airway diameters
What is the total pressure exerted by all gases in the atmosphere?
760 mm Hg
According to Dalton's Law, what is the relationship between the partial pressure of a gas and its percentage in the atmosphere?
The partial pressure is directly proportional to its percentage
What is the primary factor that governs the movement of gases between the alveoli and blood in the lungs?
Henry's Law
Which gas is more soluble in water?
Carbon dioxide
What is the primary site of gas exchange?
The alveoli
What determines the rate at which a gas dissolves in a liquid?
The partial pressure of the gas
What is the primary function of the negative intrapleural pressure?
To keep the lungs inflated
What is the main factor that reduces the surface tension of alveolar fluid?
Surfactant
What happens to the pleural cavity as the lung moves away from the thoracic wall?
It becomes slightly larger
What is the effect of the elasticity of the thoracic wall on the pleural cavity?
It increases the size of the pleural cavity
What is the result of the combination of the three main factors that contribute to negative intrapleural pressure?
The lungs are inflated
What is the direction of the force exerted by the surface tension of alveolar fluid on the lung?
Inward
What is the primary effect of restrictive disorders on total lung capacity?
Reduction in total lung capacity
What is the purpose of measuring forced vital capacity (FVC)?
To measure the amount of gas forcibly and rapidly expelled after taking a deep breath
In obstructive diseases, what changes occur in TLC, FRC, and RV?
Increase in TLC, FRC, and RV
What is the primary difference between alveolar ventilation rate and minute ventilation?
AVR measures gas flow into the alveoli, while minute ventilation measures total gas flow
What is the primary characteristic of non-respiratory air movements?
They result from reflex actions
What is the direction of gas diffusion during gas exchange?
Oxygen and carbon dioxide diffuse in opposite directions
What is the primary response of local arterioles to a low PO2 in the alveoli?
Vasoconstriction to redirect blood flow
When airflow through a bronchiole is higher than normal, what is the resulting effect on PCO2?
PCO2 decreases
What is the primary consequence of a thickened respiratory membrane on gas exchange?
Impaired gas exchange
What is the primary adaptation of the bronchioles to changes in airflow and blood supply?
Constriction in response to low airflow and dilation in response to high airflow
What is the primary consequence of a reduction in alveolar surface area on gas exchange?
Impaired gas exchange
What is the primary response of the bronchioles to an increase in PCO2 in the alveoli?
Dilation to increase airflow
This quiz covers the concept of intrapleural pressure, its negativity, and its role in keeping lungs inflated. It also explores the factors contributing to negative intrapleural pressure, including surface tension and lung elasticity.
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